I ordered several of these in late 2011 to replace the batteries in our aging fleet of portable power units. These are the exact same size and hold significantly more power. We use the powertable power packs to power pumps, inflate tires, and jump start vehicles in a pinch, but mostly to power small equipment. From November 2011 to now, March 2014, they have held up great. The fact that they get used and abused weekly or daily and held up this long is a testament to the product. Thanks, ordering again soon!